A light-emitting device using an organic EL panel having an organic EL element as a light-emitting source has been proposed. A light-emitting device using an organic EL panel is characterized in that it is surface-emitting and there is no limitation on its shape, and such a characteristic cannot be obtained by other light-emitting devices such as LED (light-emitting diode) light-emitting devices. Therefore, further developments are expected toward its practical application in the future.
Generally, an organic EL panel as a light-emitting source of a light-emitting device includes: an anode formed from a transparent conductive film such as ITO formed on a transparent substrate; a cathode formed from a metal such as Al; and an organic light-emitting functional layer having an organic multi-layer structure interposed in between the anode and the cathode (Patent Literature 1). The organic light-emitting functional layer is formed from an organic material, and is a laminate formed from a hole injection/transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer in this order from the anode side, for example. The laminate can be made by using a vacuum deposition method or an inkjet method, for example. In such an organic EL panel, the organic light-emitting functional layer is formed in a stripe pattern so that a high brightness can be obtained across the entire panel.
Arranging a plurality of such organic EL panels in a planar pattern (called “tiling”) enables a novel form of lighting, such as a light-emitting ceiling or a light-emitting wall, and it is expected to provide a new value to our daily life.
There is one form of lighting using tiling, in which all the organic EL panels are lit and turned off at the same time. This can be realized simply by turning on/off the power of all the organic EL panels.
Another form of lighting is a form in which the ceiling as a whole or the wall as a whole is used for stage-effect lighting by individually controlling a plurality of organic EL panels. For example, it is possible to express two-dimensional meaningful information or a pattern by controlling the brightness or the color of each organic EL panel.
The DMX512-A standard is a lighting control technique suitable for controlling an organic EL panel for such stage-effect lighting.
A lighting system using the DMX512-A standard is premised on the configuration with one master device responsible for lighting control, and a plurality of lighting modules (slave devices) to be subjected to the lighting control. Where the DMX512-A standard is applied to a lighting system in which a plurality of organic EL panels are tiled as described above, the master device transmits a command including control data to each of a plurality of lighting modules via a communication line, and each of the plurality of lighting modules including an organic EL panel receives the command to drive the organic EL panel according to the control data in the command.